1RG-CART will be administered intravenously. As the CAR T-cells are designed to survive and proliferate on encountering antigen, no direct relationship is anticipated between cell dose and either efficacy or toxicity. Rather, clinical benefit is more likely to be observed in those patients in whom in vivo expansion successfully occurs. A possible key determinant of expansion will be prior lymphodepletion of the patients. For this reason this trial is designed to evaluate a phased introduction of lymphodepletion in successive patient cohorts, rather than T-cell dose escalation. Only if there is insufficient expansion of T-cells following full lymphodepletion will the T-cell dose be escalated.